Proximity regulation system for use with a portable cell phone and a method of operation thereof

ABSTRACT

A proximity regulation system for use with a portable cell phone and a method of operating the same. In one embodiment, the proximity regulation system includes a location sensing subsystem that is configured to determine a location of the portable cell phone proximate a user. A power governing subsystem is coupled to the location sensing subsystem and configured to determine a proximity transmit power level of the portable cell phone based on the location.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention is directed, in general, to a mobiletelecommunications device and, more specifically, to a system and methodof determining a proximity transmit power level of a portable cell phonebased on a proximity to a user.

BACKGROUND OF THE INVENTION

[0002] Since the inception of the wireless or cellular (“cell”) phone inthe late 1940's, cell phone usage has expanded beyond their utilitarianbeginnings. Presently, cell phones are being used in every aspect ofbusiness along with every facet of personal life. People of all ages arenow using cell phones as the price of cell phones and services decrease.Presently, more than 74 million cell phones are in use in the UnitedStates with estimates predicting more than 139 million in a few years.Cell phones are moving beyond communication tools, and are now taking aplace in history by weaving themselves into the social fabric bybecoming fashion statements and symbols of power and importance.

[0003] Along with the increase in usage has come the requests forimproved service and communication quality. Consumers are now lookingfor more than just wireless voice communication but also Internetaccess, calendars, organizers, and even games. Meanwhile, manufacturersstruggle to meet consumer demands for more options and better quality ofservice.

[0004] Typically, the quality of service of a cell phone is proportionalto the transmit power level of the cell phone. Though no definite proofhas been determined, health concerns have arisen due to the power usedto transmit the radio frequency of cell phones when operated close tothe body of a cell phone user. For example, when held close to the ear,many users have health concerns about the high levels of radio frequencyenergy causing damage to brain cells.

[0005] Most of the concerns from consumers center around using the cellphone close to the ear or head of a user. New studies, however, havealso suggested that cell phone usage may possibly cause stomach cancerwhen located near the midsection when sending and receiving data textmessaging. Cell phone users still want the best possible quality ofservice from their cell phone. However, health concerns regarding thetransmit power of cell phones are now beginning to affect some users.

[0006] Manufacturers have tried several options to relieve the fears ofconsumers. One such option involves permanently reducing the power ofthe transmitter in cell phones. Though this may be perceived as a safetyadvantage to some customers, unfortunately, this also reduces thequality of service of the cell phone. Another option for consumers isthe use of cell phones with a base that typically allows a highertransmit power level of up to three watts. This may be the case for acell phone that is permanently mounted, such as in an automobile. Thesetype of cell phones, however, do not allow the flexibility demanded byconsumers that is found in the use of a portable cell phone.

[0007] Accordingly, what is needed in the art is a system and method toautomatically reduce the transmit power level of a portable cell phonewhen located near a human body thereby decreasing the perception ofhealth risks associated with the use thereof.

SUMMARY OF THE INVENTION

[0008] To address the above-discussed deficiencies of the prior art, thepresent invention provides a proximity regulation system for use with aportable cell phone. In one embodiment, the proximity regulation systemincludes a location sensing subsystem that is configured to determine alocation of the portable cell phone proximate a user. A power governingsubsystem is coupled to the location sensing subsystem and configured todetermine a proximity transmit power level of the portable cell phonebased on the location.

[0009] In another aspect, the present invention provides a method ofoperating a portable cell phone including determining a location of theportable cell phone proximate a user. The method further includesproviding a control signal based on the location, and determining aproximity transmit power level of the portable cell phone based on thecontrol signal.

[0010] In yet another aspect, the present invention provides a portablecell phone that includes a power circuit as a function of a position toa communications tower and a proximity regulation system. The proximityregulation system includes a location sensing subsystem that determinesa location of the portable cell phone proximate a user. The proximityregulation system also includes a power governing subsystem, coupled tothe location sensing subsystem, that determines a proximity transmitpower level of the portable cell phone based on the location.

[0011] The foregoing has outlined, rather broadly, preferred andalternative features of the present invention so that those skilled inthe art may better understand the detailed description of the inventionthat follows. Additional features of the invention will be describedhereinafter that form the subject of the claims of the invention. Thoseskilled in the art should appreciate that they can readily use thedisclosed conception and specific embodiment as a basis for designing ormodifying other structures for carrying out the same purposes of thepresent invention. Those skilled in the art should also realize thatsuch equivalent constructions do not depart from the spirit and scope ofthe invention in its broadest form.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] For a more complete understanding of the present invention,reference is now made to the following descriptions taken in conjunctionwith the accompanying drawings, in which:

[0013]FIG. 1 illustrates a network diagram of an embodiment of acellular telephone network employing a portable cell phone constructedin accordance with the principles of the present invention;

[0014]FIG. 2 illustrates a block diagram of an embodiment of a portablecell phone employing a proximity regulation system constructed inaccordance with the principles of the present invention; and

[0015]FIG. 3 illustrates a flow diagram of an embodiment of a method ofoperating a portable cell phone constructed in accordance with theprinciples of the present invention.

DETAILED DESCRIPTION

[0016] Referring initially to FIG. 1, illustrated is a network diagramof an embodiment of a cellular telephone network, generally designated100, employing a portable cell phone 120 constructed in accordance withthe principles of the present invention. The cellular telephone network100 includes a communications tower 110 in communication with theportable cell phone 120, employable by a portable cell phone user 150.The portable cell phone 120 includes an antenna 125, a power circuit 130and a proximity regulation system 140.

[0017] The communications tower 110 is a conventional communicationstower that is positioned to communicate with the portable cell phone120. The communications tower 110 may provide either analog or digitalcommunications depending on the cellular telephone network 100 beingused. For more information regarding communications towers and their usein cellular telephone networks, see “Mobile Communications Engineering:Theory and Applications” by William C. Y. Lee, McGraw Hill (1997), whichis incorporated herein by reference.

[0018] In the illustrated embodiment, the portable cell phone 120 is adigital cell phone capable of receiving both voice and text messaging.In an alternative embodiment, the portable cell phone 120 may also becapable of using a headset attachment to allow hands-free operation. Theportable cell phone 120 may also attach to a belt clip for storage orfor use in conjunction with a headset attachment. In addition, theportable cell phone 120 may also allow hands-free operation while storedin a cradle. The cradle may be a conventional cradle, which isconstructed to hold or store the portable cell phone 120.

[0019] The antenna 125 is a conventional portable cell phone antennathat provides communications between the portable cell phone 120 and thecommunications tower 110. Through the antenna 125, the portable cellphone 120 sends and receives voice or data communications across thecellular telephone network 100 via the communications tower 110.

[0020] In the illustrated embodiment, the power circuit 130 may be atypical power circuit in the portable cell phone 120 that produces atransmit power level equivalent to, for instance, a maximum transmitpower level of one watt. Through communications with the communicationstower 110 employing the antenna 125, the power circuit 130 may alsoprovide a network adjusted transmit power level that is lower than themaximum transmit power level of one watt. The network adjusted transmitpower level is based on a transmit signal strength of a communicationspath between the communications tower 110 and the portable cell phone120.

[0021] In an advantageous embodiment of the present invention, the powercircuit 130 is further coupled to the proximity regulation system 140that determines a proximity transmit power level of the portable cellphone 120 based on its location proximate the portable cell phone user150. Though not illustrated in FIG. 1, the proximity regulation system140 includes a location sensing subsystem and a power governingsubsystem, which cooperate to determine both the proximity transmitpower level and when it may be employed. Both the location sensingsubsystem and the power governing subsystem are more fully discussedwith respect to FIG. 2.

[0022] The proximity regulation system 140 in the illustratedembodiment, is a dedicated device that is constructed of special-purposehardware employing a software program, which directs its operation. Inan alternative embodiment, the proximity regulation system 140 may beintegrated into a power algorithm employing software that controls thepower circuit 130. The proximity regulation system 140 may be installedwhen the portable cell phone 120 is constructed. Alternatively, theproximity regulation system 140 may be an after market addition to thealready constructed portable cell phone 120. In one embodiment, theproximity regulation system 140 may be installed with a switch thatallows the portable cell phone user 150 to disengage the proximityregulation system 140. In another embodiment, the proximity regulationsystem 140 may be used with a personal digital assistant or any otherportable device that may emit radio frequency energy within the vicinityof a user.

[0023] The portable cell phone user 150 is typically anyone who uses aportable cell phone. This, of course, includes children through senioradults. In the illustrated embodiment, the portable cell phone user 150is using the portable cell phone 120 proximate their head.Alternatively, the portable cell phone user 150 may use the portablecell phone 120 while attached to a belt clip or in conjunction with aheadset. In another embodiment, the portable cell phone user 150 may usethe portable cell phone 120 for data text messaging. In this case, theportable cell phone 120 may be typically located in front of theportable cell phone user 150 and within a distance of an arm's length.It is also contemplated that the portable cell phone 120 may transmitand receive other forms of multimedia communications such as video.

[0024] Turning now to FIG. 2, illustrated is a block diagram of anembodiment of a portable cell phone, generally designated 200, employinga proximity regulation system 210 constructed in accordance with theprinciples of the present invention. The portable cell phone 200includes the proximity regulation system 210, a power circuit 240, aheadset operation mode input 250, a belt clip sensor 260 and a datatransfer operation mode circuit 270. The portable cell phone 200 isattached to a belt clip 280 having a position indicator 290. Theproximity regulation system 210 includes a location sensing subsystem220 and a power governing subsystem 230.

[0025] The proximity regulation system 210 determines a proximitytransmit power level of the portable cell phone 200 based on thelocation of the portable cell phone 200 proximate a portable cell phoneuser. In the illustrated embodiment, the proximity regulation system 210is a dedicated device that is solely hardwired. As discussed above withrespect to FIG. 1, the proximity regulation system 210 is coupled to thepower circuit 240. Additionally, the proximity regulation system 210 iscoupled to the headset operation mode input 250, the belt clip sensor260 and the data transfer operation mode circuit 270. Of course, aportable cell phone may still employ the proximity regulation system 210without the headset operation mode input 250, the belt clip sensor 260or the data transfer operation mode circuit 270.

[0026] The location sensing subsystem 220 is coupled to the powergoverning subsystem 230, and determines a location of the portable cellphone 200 proximate a user. In the illustrated embodiment, the locationsensing subsystem 220 is embodied in an integrated circuit. In anotherembodiment, the location sensing subsystem 220 may be embodied as asequence of operating instructions.

[0027] In an exemplary embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is proximate the head of theuser if there is no indication that the portable cell phone 200 is in adata transfer operation mode, a headset operation mode or located on abelt clip. In another embodiment, the location sensing subsystem 220 maydetermine if the portable cell phone 200 is proximate the head of theuser through a designated sensor 225 located on the portable cell phone200.

[0028] The designated sensor 225 may be an inductively coupled loop thatchanges a surrounding magnetic field when in the vicinity of the user'shead. The change in the magnetic field creates a change in the inductivecoupling thereby causing an impedance change associated with theinductively coupled loop. The impedance change may affect the currentflow in the inductively coupled loop, which can be used to indicate theproximity of the portable cell phone 200 to the user's head.

[0029] In an alternative embodiment, the designated sensor 225 may alsobe a contact sensor that indicates proximity of the portable cell phone200 to the user's head when the portable cell phone 200 is touching theuser's ear. The contact sensor may also indicate proximity of theportable cell phone 200 to the user by contact from the user's hand. Oneskilled in the pertinent art will understand that other sensors may beused to indicate the proximity of the portable cell phone 200 to theuser's body.

[0030] In an alternative embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is proximate the body of theuser when receiving an indication from the data transfer operation modecircuit 270. Additionally, the location sensing subsystem 220 maydetermine that the portable cell phone 200 is proximate the body of theuser if the portable cell phone 200 is located on the belt clip 280 or aheadset is inserted in the headset operation mode input 250. Still,another embodiment may indicate that the portable cell phone 200 is awayfrom the body of the user when the portable cell phone 200 is in acradle.

[0031] The power governing subsystem 230 is coupled to the locationsensing subsystem 220. The power governing subsystem 230 determines theproximity transmit power level of the portable cell phone 200 based onthe location of the portable cell phone 200 as determined by thelocation sensing subsystem 220. In one embodiment, the network adjustedtransmit power level may be reduced to a value determined by theproximity transmit power level when the location of the portable cellphone 200 is within the vicinity of the user's head. In anotherembodiment, the network adjusted transmit power level may be similarlyreduced when the location of the portable cell phone 200 is just withinthe vicinity of a user's body.

[0032] In another embodiment, the proximity transmit power level maymatch the network adjusted transmit power level, which may be themaximum transmit power level of, for instance, one watt, when theportable cell phone 200 is operating in the headset operation mode orthe data transfer mode. In still another embodiment, the proximitytransmit power level may be further reduced when the portable cell phoneuser is a child. A switch 235 may be installed on the portable cellphone 200 to allow this user option. Additionally, the switch 235 mayalso allow the user to disengage the proximity regulation system 210whenever desired. In one embodiment, the switch 235 may be a standardsoftware switch that the user controls through a display and a keypad ofthe portable cell phone 200.

[0033] The headset operation mode input 250 is a conventional receptaclefor receiving a headset that allows hands-free operation. As mentionedabove, the headset operation mode input 250 is coupled to the proximityregulation system 210. The location sensing subsystem 220 of theproximity regulation system 210 receives an indication that the headsetis in use from the headset operation mode input 250 when a headset isinserted. In one embodiment, the location sensing subsystem 220determines that the portable cell phone 200 is not within the vicinityof the head of the user upon receiving indication from the headsetoperation mode input 250.

[0034] In another embodiment, the location sensing subsystem 220 maydetermine that the portable cell phone 200 is within the vicinity of theuser's body if the headset is inserted in the headset operation modeinput 250. In an alternative embodiment, the location sensing subsystem220 may determine that the headset operation mode input 250 may be usedin conjunction with the belt clip sensor 260 to indicate that theportable cell phone 200 is proximate the user's body.

[0035] The belt clip sensor 260 is coupled to the proximity regulationsystem 210 and indicates when the portable cell phone 200 is locatedwithin the belt clip 280. The belt clip sensor 260 may be a contactsensor that is depressed by a protrusion on the belt clip 280 whenplaced in the belt clip 280. In an alternative embodiment, the belt clipsensor 260 may use an inductively coupled loop constructed to indicateto the location sensing subsystem 220 that the portable cell phone 200is in the belt clip 280.

[0036] The data transfer operation mode circuit 270 is coupled to theproximity regulation system 210 and indicates to the location sensingsubsystem 220 of the proximity regulation system 210 when the portablecell phone 200 is being used for data text messaging. As mentioned abovewith respect to the discussion of the antenna 125 of FIG. 1, the datatext messaging may be received from a communications network via anantenna such as those shown in FIG. 1.

[0037] The belt clip 280 is a conventional device for holding theportable cell phone 200. The belt clip 280 is typically constructed ofplastic and constructed to attach to a user's belt. The belt clip 280may hold the portable cell phone 200 when the user is not using theportable cell phone 200. In alternative embodiments, the belt clip 280may hold the portable cell phone 200 when the headset is being employed.In other embodiments, another type of clip may be used by the user tohold the portable cell phone 200. For example, instead of the belt clip280, the user may store the portable cell phone 200 in a clip thatattaches to a shirt pocket or an arm band.

[0038] The position indicator 290 of the belt clip 280 may be aprotrusion that depresses the belt clip sensor 260 on the portable cellphone 200 to indicate to the location sensing subsystem 220 that theportable cell phone 200 is positioned in the belt clip 280. In analternative embodiment, the position indicator 290 may be a metallicinsert that varies the magnetic field of an inductively coupled loop ofthe belt clip sensor 260. It should be noted that other pertinentcomponents not shown may be included within the portable cell phone 200without departing from the scope of the present invention.

[0039] Turning now to FIG. 3, illustrated is a flow diagram of anembodiment of a method, generally designated 300, of operating aportable cell phone constructed in accordance with the principles of thepresent invention. The method 300 starts in a step 305 with an intent tooperate a portable cell phone.

[0040] Following the step 305, the portable cell phone determines itslocation proximate a user in a step 310. In one embodiment, the locationmay be determined by a designated sensor that indicates the proximity ofthe portable cell phone to a user's head. In alternative embodiments,the location may be determined by other sensors including a belt clipsensor, a cradle sensor, or a headset sensor.

[0041] After determining proximity to the user, the portable cell phoneprovides a control signal in a step 320. The control signal may, forinstance, be either a voltage level or current level that is designatedto correspond to the previously determined location. Those skilled inthe pertinent art will understand the use of control signals torepresent a determined condition.

[0042] After providing a control signal, the portable cell phonedetermines if the control signal indicates proximity of the portablecell phone to the user in a first decisional step 330. In oneembodiment, various control signals may be designated to correspond todifferent locations of the portable cell phone proximate the portablecell phone user. For example, one control signal may represent that theportable cell phone is in the vicinity of the user's head. Anothercontrol signal may be used to represent that the portable cell phone isin the vicinity of the user's body. In alternative embodiments, thecontrol signal may represent that the portable cell phone is not withinthe vicinity of the user's body.

[0043] In the illustrated embodiment, if it is determined that theportable cell phone is proximate the user, then the transmit power levelis reduced as determined by a value of a proximity transmit power level,in a step 340. In one embodiment, the transmit power level may bereduced to one network adjusted transmit power level whenever theportable cell phone is within the vicinity of any part of the user'sbody. In another embodiment, the transmit power level may be reduced tovarious allowable proximity transmit power levels depending on thevicinity of the portable cell phone to different parts of the user'sbody.

[0044] After adjusting the transmit power level, the portable cell phonethen transmits at a reduced level in a step 350. In one embodiment, theadjusted transmit power level may not exceed the network adjustedtransmit power level as determined by the communications path betweenthe portable cell phone and the communications tower. In otherembodiments, the adjusted transmit power level may be reduced to theproximity transmit power level. Finally, the transmission of theportable cell phone ends in a step 370.

[0045] Returning now to the first decisional step 330, if the portablecell phone is not proximate the user, then the method 300 proceeds to astep 360 wherein the portable cell phone transmits at the networkadjusted transmit power level. In one embodiment, the network adjustedtransmit power level may equal the maximum transmit power level of aportable cell phone. In other embodiments, the network adjusted transmitpower level may be a reduction from the maximum transmit power level dueto the communications path between the communications tower and theportable cell phone. After transmitting in step 370, the method 300 endsin the previously mentioned step 360.

[0046] Although the present invention has been described in detail,those skilled in the art should understand that they can make variouschanges, substitutions and alterations herein without departing from thespirit and scope of the invention in its broadest form.

What is claimed is:
 1. For use with a portable cell phone, a proximity regulation system, comprising: a location sensing subsystem configured to determine a location of said portable cell phone proximate a user; and a power governing subsystem, coupled to said location sensing subsystem, configured to determine a proximity transmit power level of said portable cell phone based on said location.
 2. The proximity regulation system as recited in claim 1 wherein said proximity transmit power level is reduced when said location is within a vicinity of a user's head.
 3. The proximity regulation system as recited in claim 1 wherein said proximity transmit power level is limited to a predetermined maximum level.
 4. The proximity regulation system as recited in claim 1 wherein said proximity transmit power level is maximum when said portable cell phone is operating in a headset operation mode or data transfer operation mode.
 5. The proximity regulation system as recited in claim 1 wherein said portable cell phone is located on a belt-clip of said user.
 6. The proximity regulation system as recited in claim 1 wherein said location sensing subsystem or said power governing subsystem is embodied in an integrated circuit.
 7. The proximity regulation system as recited in claim 1 wherein said location sensing subsystem or said power governing subsystem is embodied in a sequence of operating instructions.
 8. The proximity regulation system as recited in claim 1 wherein said location sensing subsystem determines said location by employing a sensor selected from the group consisting of: a designated sensor, a contact sensor, a belt clip sensor, and a cradle sensor.
 9. The proximity regulation system as recited in claim 1 wherein said location sensing subsystem determines said location by ascertaining a mode of operation of said portable cell phone.
 10. A method of operating a portable cell phone, comprising: determining a location of said portable cell phone proximate a user; providing a control signal based on said location; and determining a proximity transmit power level of said portable cell phone based on said control signal.
 11. The method as recited in claim 10 wherein said proximity transmit power level is reduced when said location is within a vicinity of a user's head.
 12. The method as recited in claim 10 wherein said proximity transmit power level is limited to a predetermined maximum level.
 13. The method as recited in claim 10 wherein said proximity transmit power level is maximum when said portable cell phone is operating in a headset operation mode or data transfer operation mode.
 14. The method as recited in claim 10 wherein said portable cell phone is located on a belt-clip of said user.
 15. The method as recited in claim 10 wherein said determining said location is performed by a location sensing subsystem embodied in an integrated circuit.
 16. The method as recited in claim 10 wherein said determining a proximity transmit power level is performed by a power governing subsystem embodied in a sequence of operating instructions.
 17. The method as recited in claim 10 wherein said determining a location employs a sensor selected from the group consisting of: a designated sensor, a contact sensor, a belt clip sensor, and a cradle sensor.
 18. The method as recited in claim 10 wherein said determining a location is performed by ascertaining a mode of operation of said portable cell phone.
 19. A portable cell phone, comprising: a power circuit that provides a network adjusted transmit power level as a function of a position to a communications tower; and a proximity regulation system, including: a location sensing subsystem that determines a location of said portable cell phone proximate a user; and a power governing subsystem, coupled to said location sensing subsystem, that determines a proximity transmit power level of said portable cell phone based on said location.
 20. The portable cell phone as recited in claim 19 wherein said proximity transmit power level is reduced when said location is within a vicinity of a user's head.
 21. The portable cell phone as recited in claim 19 wherein said proximity transmit power level is limited to a predetermined maximum level.
 22. The portable cell phone as recited in claim 19 wherein said proximity transmit power level is maximum when said portable cell phone is operating in a headset operation mode or data transfer operation mode.
 23. The portable cell phone as recited in claim 19 wherein said portable cell phone is located on a belt-clip of said user.
 24. The portable cell phone as recited in claim 19 wherein said location sensing subsystem or said power governing subsystem is embodied in an integrated circuit.
 25. The portable cell phone as recited in claim 19 wherein said location sensing subsystem or said power governing subsystem is embodied in a sequence of operating instructions.
 26. The portable cell phone as recited in claim 19 wherein said location sensing subsystem determines said location by employing a sensor selected from the group consisting Of: a designated sensor, a contact sensor, a belt clip sensor, and a cradle sensor.
 27. The portable cell phone as recited in claim 19 wherein said location sensing subsystem determines said location by ascertaining a mode of operation of said portable cell phone. 